"Amoliya" mineral fiber acoustic ceiling board is your best choice of ceiling decorative material. Excellent sound absorption and special decorative effects give you a new feeling. Appearance quality Surface with no stains, scratches, and uneven color;Product must not have cracks, debris, warping, distort;No defect of the missing angle on effection of application and decoration. Size deviation allowable Lenth:±2.0 mm wide:±2.0mm Degree of right-angle deviation: 3/1000 Bulk density,kg/m3: 300 Moisture content:<3.0 Bending failure load,N:>60 Damp disturbance degree,mm:<3.5 NRC: 0.5~0.65 RH:>=85% Any demand, pls do not hesiatate to contact us . Looking forward to your early reply. B.Rgds Sarra Yue